Dredge.



J. R. HART & J. R. DAVIS.

I DREDGE. 7 APPLICATION FILED DEC. H. 1914. 1,1 59,937. I Patented Nov. 9, 1915.

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JOHN ROBERT HART AND JOHN ROBERT DAV IS, OF TAMPA, FLORIDA.

DREDG-E.

Application filedllecemher 11', 1914.

To all whom it may concern:

Be it known that we, JOHN R. HART and JOHN It. DAVIS, citizens of the United States, and residents of Tampa, in the county of Hillsborough and State of Florida, have made certain new and useful Improvements in Dredges, of which the following is a specification.

Our invention relates to improvements in dredges and it consists in the combinations,

constructions, and arrangements herein described and claimed.

An object of our invention is to provide a dredge of the suction type in which the liability of clogging of the blades is reduced, owing to the provision of a scraper on the inside of the cutter blades.

A further object of our invention is to provide a scraping device of the type described which may be readily adjustedor applied to the device without the necessity of removing the cutter blades.

Other objects and advantages will appear in the following specification and the novel features of the device will be particularly pointed out in the appended claims.

Our invention is illustrated in the accompanying drawings forming part of this application in which Figure 1 is a side view of a portion of a dredge showing the cutters and their relation to the suction pipe, Fig. 2 is an enlarged section along the line 22 of Fig. 1, Fig. 3 is a perspective view of the scraper. Fig. 4 is a view of a modified form of scraper blade.

In Fig. 1 we have shown a portion of a suction dredge in which the ladder frame 1 supports a suction pipe 2, which terminates at or adjacent to the ladder head 3. Carried by the ladder frame 1 in bearings f and 5 respectively, the former on the lad der frame and the latter on the ladder head, is a cutter shaft 6 which is driven by any suitable power means. The end of the cutter shaft 6 projects beyond the suction pipe and is arranged to receive a wheel 7 to which is secured a series of cutter blades 8, these blades being preferably of the shape shown in the drawings and being disposed symmetrically with respect to the cutter shaft. As will be seen from Fig. 1, the blades are inclined both with respect to the axis of the cutter shaft and also with respect to radial planes through the cutter shaft, so as to facilitate the cutting and the projection of Specification of Letters Patent.

Patented Nov. 9, 1915.

Serial No. 876,654.

the solid matter rearwardly, toward the open end of the suction pipe, from whence it is carried by means of the flow of water and deposited in the usual manner.

It often happens that the blades will accumulate muck, peat, or other adhesive substances, thereby clogging them up andrendering them less eificient and to prevent such clogging we provide a stationary scraper blade, of the shape shown in Fig. 3. This consists of a body portion 9, which is disposed just inside of the cutter blades 8, and which is provided at one end with a laterally extending flange 9 arranged to be bolted to an extension of the ladder head 3. The blade 9 is curved inwardly and terminates in a forked portion 9 arranged to straddle the cutter shaft.

The ladder frame bearing the cutter and suction pipe is manipulated by means of a boom 10, pulleys 11, and ropes 12 in the usual manner. 7 From the foregoing description of the various parts of the device the operation thereof may be readily understood. In the operation of this device the cutter is thrust forward in the usual manner and the cutter shaft 6 is revolved by any suitable power means (not shown). The blades 8 cut the sediment or dirt and owing to the rapid revolution of the blades, it is carried upwardly and flows, with the water which is being drawn into the suction pipe, through the latter, where it can be deposited in any suitable place. The tendency of the blades is to clog up on their inner sides due to the fact that many times portions of the material to be dredged, such as muck, peat, etc., are encountered. These tend to add weight to the blades therefore requiring more power to drive them and also interfering with the proper cutting of the blades.

The provision of the stationary blade 9 insures the removal of any muck or other substances which may adhere to the blades and which projects far enough to come in contact with the stationary blade during the revolution of the cutter blades. Thus the blades are kept clean and are thereby rendered more eflicient.

In Fig. 4 we have shown a view of a modified form of scraper blade in which a body portion 9 is provided with a laterally bent end 9 which may be secured to the head 5 and which does not. engage the shaft and which is shorter than the blade 9. The

blade shown in Fig. 4: is especially designed for cutting clay from the revolving blades 8.

We claim:

1. In a dredge, the combination with a suction pipe, of a cutter blade shaft disposed adjacent thereto and extended beyond the end of the suction pipe, cutter blades secured to the extended end of said shaft, said cutter blades being inclined toward the axis of the shaft at the ends farthest from the suction pipe, and a stationary scraper disposed between said blades and the shaft, the edge of said scraper being adjacent to the path described by the inner edge ofthe blades.

2. In a dredge, the combination with. a

' suction pipe, of a cutter blade shaft disposed adjacent thereto and extended beyond the end of the suction pipe, cutter blades secured to the extended end of said shaft, said cutter blades'being inclined toward the axis of the shaft at the ends farthestfrom the suction pipe, and a stationary scraper disposed between said blades and the shaft, the edge of said scraper being adjacent to the path described by the inner edge of the blades, one end of said scraper being rigidly Copies of this patent may be obtained for five cents each, by addressing the Commissioner Washington, D. 0.

shaft at the ends farthest from the suction pipe, and a stationary scraper disposed between said blades and the shaft, the edge of said scraper being adjacent to the path described by the inner edge of the blades, one end of said scraper being provided with a laterally extending flange for securing the scraper to a portion ofthe supporting frame of the suction pipe and the other end of the scraper being bent laterally and being provided with a fork, the arms of the fork straddling the cutter blade shaft.

JOHN ROBERT HART. JOHN ROBERT DAVIS.

Witnesses:

P. C. KELLY, V LEwIsG. THOMPSON.

of Patents, 

